1. Field of the Invention
The present invention relates generally to percussion instruments and more specifically to damping a vibrating surface of a percussion instrument.
2. Background Information
Percussionists often desire to damp their musical instruments, for example drums, in order to control or change the sound emanating from the instruments. To better understand damping, it is useful to review how a drum produces a distinctive sound.
A drum is basically a tensioned membrane fixed over a resonating chamber, enclosed by a rigid shell, typically cylindrical in shape. The membrane (commonly referred to as the drumhead) is often made of biaxially-oriented polyethylene terephthalate polyester (commonly referred to by the trade name Mylar® registered to DuPont Teijin Films L.P.), though animal skins and other poly-spun fibers are also used. A drum's distinctive sound is actually a combination of two different sounds; “attack,” which is the sound made by a drumstick or hand striking the drumhead, and “resonance,” which is the sound produced by vibrations of a resonating chamber of the drum. When the drumhead is struck, vibrations of the drumhead are transmitted to the shell at a bearing edge where the drumhead meets the shell (often termed a counterhoop or rim). Also, movement of the drumhead causes air to impact the interior walls of the shell and a bottom membrane (bottomhead) of the drum. All these vibrations interact to produce a resonance.
Any modification of a vibrating surface of a percussion instrument generally affects the vibrations produced. For example, modification of a drumhead has a dramatic effect on a drum's sound. Accordingly, musicians have employed various techniques to change the sound of percussion instruments, often by attempting to damp the instruments.
For example, U.S. Pat. No. 4,745,839 discloses a damping structure that includes an inflatable balloon-like cushioning member that may be mounted inside a drum to contact with an interior face of the drumhead. The cushioning member is attached to a rod that spans the drum, holding it in place.
By way of further example, U.S. Pat. No. 5,637,819 discloses a self-adhesive gel patch that adheres to a vibrating percussion instrument surface. The gel in the gel patch is primarily composed of a PVC copolymer resin.
Yet, these and other existing techniques have been found unsatisfactory in practice. Damping systems disposed inside of a percussion instrument are often cumbersome to install and difficult to add or remove quickly, as often required during a musical performance. Further, assemblies disposed inside a percussion instrument have a tendency to produce rattles and other unpleasant sounds. Similarly, existing systems that damp by attaching to the exterior of a percussion instrument suffer a variety of shortcomings. Such systems typically use adhesives that may transfer to or soil the surface of the percussion instrument, or lose their adhesive properties over time. Even when new, such known adhesive based systems commonly do not adhere well, and due to a lack of adhesion, provide insufficient damping effect. Other systems may use colloidal suspensions or gels, yet these systems also often lose their adhesive properties over time. Further, devises employing colloidal suspensions or gels often do not feel responsive when struck and therefore limit a musician's options in performances.